Through this page, you can stay up to date about the latest developments on avian influenza. Wageningen Bioveterinary Research (WVBR) takes care of diagnostics in The Netherlands.
What is avian influenza?
Bird flu or avian influenza (AI) is a collective term for different influenza viruses that may be dangerous to poultry. Especially chickens, turkeys, waterfowl, waders, beach birds, ratites and starlings are susceptible to avian influenza, with possible lethal consequences. Some forms are also transmissible to humans.
Mild and hazardous avian influenza
Avian influenza has two variants: a mild variant and a hazardous variant. Most viruses are the mild variant, known as low pathogenic avian influenza (LPAI). On average about 10 to 30 introductions of the mild variant are detected annually. Birds that have been infected with this variant exhibit few disease symptoms. However, the mild form may also change into the highly contagious variant, known as high pathogenic avian influenza (HPAI). It is for this reason that companies are also culled in the case of an outbreak of a mild variant.
Bird flu in the Netherlands 2016/2017
In late 2016 and early 2017, besides wild birds, several poultry farms and household flocks were found to be infected with the highly pathogenic variant of avian influenza. Research has shown that these infections were linked to wild migratory birds.
Wild birds are often the source of avian influenza viruses. Birds, including poultry, can catch bird flu in several ways:
- Through direct contact with infected birds; the virus can be spread through the respiratory system, eye fluids and droppings
- Through contaminated materials such as food, crates, vehicles and people who have been in contact with the virus through their shoes or clothing
- Via dust from a contaminated coop (spread through the air)
In some cases people – and other mammals like pigs and foxes – can become infected. This can happen if there is direct and extensive contact between infected animals and humans, like the caretakers of the animals or those involved in culling.
The symptoms of avian influenza in humans are very mild in most cases. Serious or even fatal infections have only been reported in exceptional cases. This happened for example after infection with the HPAI H5N1 virus in Asia in 1997 and 2004, with a HPAI H7N7 in the Netherlands in 2003 and recently with a LPAI H7N9 virus in China.
The virus can enter the Netherlands through the import of live birds, eggs and egg products, poultry and poultry products as well as through travellers. Spreading via migratory birds also represents a risk.
Free-range poultry farms in the Netherlands are at greater risk of an avian influenza infection, because the poultry can come into direct contact with potentially infected wild birds and waterfowl.
There is a fear that the virus will change to make it easily transmissible among humans. This could lead to a worldwide influenza epidemic; a pandemic. Whether this will actually happen is unpredictable. Previous flu pandemics were the Spanish flu (1918), with an estimated 40 million deaths worldwide, the Asian flu (1957-58) and the Hong Kong flu (1968) with 2 to 3 million victims each.
Within the European Union legislation exists to prevent avian influenza from being introduced or spread throughout the EU via infected poultry or transport. For example, farmers and transporters of live animals must take hygienic measures to prevent infection and the spread of the virus.
Monitoring and early warning program
The Netherlands has operated a monitoring program since the HPAI H7N7 outbreak in 2003. Domestic poultry, but also wild birds, are regularly checked for antibodies to the virus. In this way, it is possible to discover avian influenza at an early stage and limit the spread of the virus (early warning programs).
Vaccination of poultry?
Vaccination of poultry is possible but there are many snags. It is costly, difficult to organise and tied to permits. Some buyers of Dutch poultry products (including Germany) do not want products from vaccinated animals.
What drives the choice of poultry market channel and the change of purchase behavior due to highly pathogenic avian influenza outbreaks?
Poultry Science 97 (2018)10. - ISSN 0032-5791 - p. 3652 - 3660.
Spatial transmission of H5N2 highly pathogenic avian influenza between Minnesota poultry premises during the 2015 outbreak
PLoS ONE 13 (2018)9. - ISSN 1932-6203
Similar transmissibility of the Italian H7N1 highly pathogenic avian influenza virus and its low pathogenic avian influenza virus predecessor
The Veterinary Journal 232 (2018). - ISSN 1090-0233 - p. 20 - 22.
Serologic evidence of West Nile virus and Usutu virus infections in Eurasian coots in the Netherlands
Zoonoses and Public Health 65 (2018)1. - ISSN 1863-1959 - p. 96 - 102.
Risk perceptions of public health and food safety hazards in poultry husbandry by citizens, poultry farmers and poultry veterinarians
Poultry Science 97 (2018)2. - ISSN 0032-5791 - p. 607 - 619.
Risk of poultry compartments for transmission of Highly Pathogenic Avian Influenza
PLoS ONE 14 (2018)2. - ISSN 1932-6203
Passive inhalation of dry powder influenza vaccine formulations completely protects chickens against H5N1 lethal viral challenge
European Journal of Pharmaceutics and Biopharmaceutics 133 (2018). - ISSN 0939-6411 - p. 85 - 95.
Novel highly pathogenic avian influenza A(H5N6) virus in the Netherlands, december 2017
Emerging Infectious Diseases 24 (2018)4. - ISSN 1080-6040 - p. 770 - 773.
Local amplification of highly pathogenic avian influenza H5N8 viruses in wild birds in the Netherlands, 2016 to 2017
Eurosurveillance 23 (2018)4. - ISSN 1025-496X
Linking supply chain governance and biosecurity in the context of HPAI control in western java : A value chain perspective
Frontiers in Veterinary Science 5 (2018). - ISSN 2297-1769
Veterinary Molecular Diagnostics
In: Molecular Diagnostics Part 2: Clinical, Veterinary, Agrobotanical and Food Safety Applications / , van Pelt-Verkuil, E., van Leeuwen, W.B., te Witt, R.. - : Springer - ISBN 9789811045110 - p. 219 - 234.
Risk for low pathogenicity avian influenza virus on poultry farms, The Netherlands, 2007–2013
Emerging Infectious Diseases 23 (2017)9. - ISSN 1080-6040 - p. 1510 - 1516.
On the role of vaccine dose and antigenic distance in the transmission dynamics of Highly Pathogenic Avian Influenza (HPAI) H5N1 virus and its selected mutants in vaccinated animals
Wageningen University. Promotor(en): M.C.M. Jong, co-promotor(en): B. Peeters. - Wageningen : Wageningen University - ISBN 9789463438063 - p.
No evidence that migratory geese disperse avian influenza viruses from breeding to wintering ground
PLoS ONE 12 (2017)5. - ISSN 1932-6203 - 11 p.
Multiple reassorted viruses as cause of highly pathogenic avian influenza A(H5N8) virus epidemic, the Netherlands, 2016
Emerging Infectious Diseases 23 (2017)12. - ISSN 1080-6040 - p. 1966 - 1973.
Genetic versus antigenic differences among highly pathogenic H5N1 avian influenza A viruses : Consequences for vaccine strain selection
Virology 503 (2017). - ISSN 0042-6822 - p. 83 - 93.
Discordant detection of avian influenza virus subtypes in time and space between poultry and wild birds; Towards improvement of surveillance programs
PLoS ONE 12 (2017)3. - ISSN 1932-6203
Different cross protection scopes of two avian influenza H5N1 vaccines against infection of layer chickens with a heterologous highly pathogenic virus
Research in Veterinary Science 114 (2017). - ISSN 0034-5288 - p. 143 - 152.
Deaths among wild birds during highly pathogenic avian influenza A(H5N8) virus outbreak, the Netherlands
Emerging Infectious Diseases 23 (2017)12. - ISSN 1080-6040 - p. 2050 - 2054.
Southward autumn migration of waterfowl facilitates cross-continental transmission of the highly pathogenic avian influenza H5N1 virus
Scientific Reports 6 (2016). - ISSN 2045-2322
Role of vaccination-induced immunity and antigenic distance in the transmission of highly pathogenic avian influenza H5N1.
Journal of the Royal Society, Interface 13 (2016)114. - ISSN 1742-5689 - 13 p.
Role for migratory wild birds in the global spread of avian influenza H5N8
Science 354 (2016)6309. - ISSN 0036-8075 - p. 213 - 217.
Quantifying potential sources of surface water contamination with Campylobacter jejuni and Campylobacter coli
Water Research 101 (2016). - ISSN 0043-1354 - p. 36 - 45.
Mutations in the haemagglutinin protein and their effect in transmission of highly pathogenic avian influenza (HPAI) H5N1 virus in sub-optimally vaccinated chickens
Vaccine 34 (2016)46. - ISSN 0264-410X - p. 5512 - 5518.
Modelling the innate immune response against avian influenza virus in chicken
PLoS ONE 11 (2016)6. - ISSN 1932-6203
Lack of virological and serological evidence for continued circulation of highly pathogenic avian influenza H5N8 virus in wild birds in the Netherlands, 14 November 2014 to 31 January 2016
Eurosurveillance 21 (2016)38. - ISSN 1025-496X - 11 p.
H7N9 live attenuated influenza vaccine is highly immunogenic, prevents virus replication, and protects against severe bronchopneumonia in ferrets
Molecular Therapy 24 (2016)5. - ISSN 1525-0016 - p. 991 - 1002.
Ethical promises and pitfalls of OneHealth
Public Health Ethics 9 (2016)1. - ISSN 1754-9973 - p. 1 - 4.
Avian Influenza in The Netherlands - Disease control and animal welfare